All right, here’s the skinny on this monstrous stadium bill: Co-headliner Kenny Chesney is beloved and quite talented. Co-headliner Tim McGraw is also a person who sings. But opener Grace Potter & the Nocturnals are the real deal. Thanks in part to frontwoman Potter’s Mystique-like ability to morph, then channel, whatever muse, era, genre or buried fetish a particular crowd demands (all without ever triggering inauthentic red alarms), the Nocturnals have opened for all kinds – Dave Matthews Band, the Black Crowes, Gov’t Mule, among others. And it’s only turned up the heat on Potter’s already white-hot flame: The band’s game-changing new album – the lead single “Never Go Back” was co-produced by the Black Keys’ Dan Auerbach – drops a couple weeks after this show. Around that time, they’ll be featured on VH1’s Storytellers and Potter’s rumored to be sitting on a solo project she made with T Bone Burnett. Of course, this particular show’s ticket prices seem like reason enough to catch them next time, except that the Nocturnals’ (let’s be honest, Potter’s) sonic heft and indefatigable live presence practically beg for giant pleasure domes to house them. Something like, say, a football stadium. – Justin Strout